Quality of bitumens in asphalt hot-mixes with emphasis on the durability of constructed premix surfacings.

Abstract

The poor performance of asphalt surfacings either during construction or in-service, can be very traumatic to contractor, client, consultant, road-user and ultimately to the taxpayer. The binder is quite often blamed, with or without justification, of being the cause of such unfortunate events. Although the binder in hot-mix asphalt is small in volume when compared to the mineral components, it nevertheless plays a very important role as a binding agent and should continue to do so for an acceptable time. Asphalt technologists' ultimate quest is for performance-related specifications that will ensure the procurement of quality bitumens which could produce asphalts with desirable performance during construction, and which will resist physical deterioration of the asphalt application over a long term of service. It is generally accepted by researchers in the field of asphalt chemistry such as Petersen (1) and Rostler and White (2) that it would be difficult to specify road bitumens on the basis of chemical composition.